Process of making rosin soap



Patented Mar. 27, 19 28.

UNITED STATES PATENT OFFICE. v

can 0. name, or rrr'rsn'onen, rnnusrrvama, nssronon r rr'nn m's'rrru'rn or summon, moonrona'rnn, or JACKSONVILLE, FLORIDA, a conrona'rrozu or nan- AWARE.

Ho Drawing.

My invention relates to the treatment of rosin and the production of rosin soap.

Rosin is a substance of wide industrial utility, but, because of, certain characteris l tics, it serves imperfectly some purposes for which it is used. In soap-making, for example, rosin is a useful substance. Added to and forming a mixture with the fattyacid compounds of which soap essentially consists, a commereial soap-.is produced which, as compared with a soap composed of fatty-acid compounds alone, is relatively inexpensive, more freely productive of lather, and of greater cleansing power. The disadvantages incident to the use of rosin as aningredient of soap are that cakes of soap which contain it are liable in time, particularly when exposed to'hui'nid air, to become moist and sticky. They also tend to grow discolored. This tendency to become moist and sticky is such'that hitherto it has not been possible to produce in satisfactory condition for' the market rosincontaining soap in the form of soap chips.

And such a commodity is a recognized desideratum.

i I have discovered, and from this discovery my invention proceeds, that by preliminary treatment of the rosin of commerce, resulting in a certain chemical change in its substance, and by an ensuing separation of constituents, substances may be obtainedv which are serviceable in the industrial arts, in-

fuller degree than rosin hasbeen known to be serviceable. .In soap-making for instance,

' the rosin derivative of my invention, when 'mixed with the. fatty-acid compounds from which soap is prepared, affords a commercial soap having the known good qualities of 40 rosin soap and free ofrthe undesirable quali ties which rosin 'soap as hitherto produced, has possessed. And, specifically, soap chips made from soap containingmy rosin derivative are stable, and become a satisfactory article of commerce, and fill a recognized want.

Abietic acid is a. desirable substance,.being useful for. various industrial purposes, and in the ractice of my invention I am able to pr uce abietic acid free of impurities and this in economical manner. 'n in varnis -makin thetreatment to w ich-I subject rosin a ords me resene, freed from abiet-ic acid. compounds, and

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Application filed July :0, i925. Serial no. 47,1ea.

chemically pure or substantially so. The so liberated resene, being a neutral gum having enhanced drying properties; serves as a valuable constituent of varnishes.

In the practice ofv my invention, and beginning with the rosin of commerce, I first, by the known means of acid treatment or heat, isomerize the material, Specifially, by heating'the rosin to a temperature of 300 C; and maintaining it at that temperature, isomerization may be effected. Or, again, if the rosin be melted, and if while it r emains in liquid condition a slow current of hydrochloric acid gas be caused to pass through it, isomerization will be effected. If while such acid treatmentis in progress stirring "be resorted to, or other means for effecting more intimate contact of the substances so brought into association, isomerization may be effected in about fifteen minutes.

Having efi'ected isomeriz'ation of the rosin, I dissolve it in a suitable solvent, such as ethyl alcohol, methyl alcohol, or other alcohol and to the solvent either before or after solution I add sodium hydroxide, or other alkali, in the amount ofone fourth of the equivalent weight of the rosin under treatment. 'A convenient degree of concentration of the sodium hydroxide em loyed would be a forty per cent, aqueous so utlon, but it will be understood that the degree of concentration does not enter into the essence of the invention, and the degree of concentration' may in fact vary indefinitely. The

The material hen is carried toss. filter ress, where the precipitate is. separated.-

he fi trate which passes on carries with it in solution the resene, and th s substance may now be recovered free 0f 8|b1el510 acid compounds. p

The precipitate which remains in the filter 10 press consists of an alkali metal (sodium) acid salt of abi etic acid. This added to the fatty-acid compounds of which soap is essentially prepared, affords a commercial soap of the excellence indicated, and a soap which may be prepared and marketed in the form of chips, which are serviceable and satisfactory.

The precipitate remainin in the filter press may be used as it is, or 1t may be purified of all trace of resene by washing it with more of the solvent. It may by pressure be freed sufiiciently of solvent, or, if more complete removal of the solvent be desired, the cake from the filter press may be heated, and the last trace of solvent may be drawn off, preferably under vacuum. The resenecontaining solvent so ultimately separated from the precipitate, may of course be re turned to the main body of solvent, and its burden of rescue in such manner saved.

The procedure here outlined may advantageously be carried out in closed system, as the practitioner of the art will well understand.

Having by the procedure described obtained'in pure condition an alkali metal acid salt of abietic acid. it remains only to treat upon the rosin of commerce a yield of pure acid amounting to seventy-five to eighty per cent by weight of the quantity of rosin treated may be recovered.

In the ensuing claims I use the term alkali metal, and I use it in its wider significance, to include ammonium.

I claim as my invention:

1. Th'cmethod herein described of producing rosin soap which consists in converting the major part of the acid component of a quantity of rosin in'to alkali acid salt, removing from such salt the rescue component of the rosin, and using the remaining salt as an ingredient in the soap-making operation.

2. The method herein described of producing rosin soap which consists in isomerizing a quantity of resin, bringing the so treated substance into solution, precipitating from such solution an alkali metal acid salt of abietic acid, separating the precipitate, and introducing the separated precipitate as an ingredient in the soap-making operation.

In testimony whereof I have hereunto set my hand.

CARL c. KF-SL'ER. 

